1. Field of the Invention
The present invention relates to a timepiece such as a portable watch like, e.g., a wristwatch and a pocket watch, a desk clock and a wall-mounted clock.
2. Description of the Prior Art
Hitherto, among wristwatches possessing a case back, there is known a wristwatch in which an annular protrusion part is formed in an inner periphery of a front side end part of a case band in which a dial is accommodated, to the inner periphery of this annular protrusion part, a glass covering the dial is fitted and fixed and a tubular part of an edge member functioning also as a bezel is fitted, and a caulking part integral with this tubular part is caulked to a back face of the annular protrusion part (for example, refer to JP-UM-B-5-37273 Gazette).
In the wristwatch in which the edge member has been caulked to the case band as mentioned above, since the fact that a caulked part having been deformed is caulked again after having been returned to a state before being caulked extremely decreases a mechanical strength of the caulked part, it is impossible to detach the edge member from the case band. For this reason, in a case where the edge member has been impaired, a user of the wristwatch is obliged to exchange not only the edge member to which the glass has been fixed but also the case band to which this edge member has been caulked.
Further, in a wristwatch in which a waterproofness has been intended by nipping a seal packing between the case band and the edge member, there is considered the fact that a performance of the seal packing decreases during a long period guarantee term of the wristwatch and thereafter. Also in a case where, in order to cope with this, it is attempted to exchange the seal packing, since it is possible to detach the edge member from the case band, it is obliged to exchange not only the edge member but also the case band to which this edge member has been caulked.